Glassy behaviour in a simple topological model

被引:20
作者
Davison, L [1 ]
Sherrington, D [1 ]
机构
[1] Univ Oxford, Dept Phys, Oxford OX1 3NP, England
来源
JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL | 2000年 / 33卷 / 48期
关键词
D O I
10.1088/0305-4470/33/48/302
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
In this paper we study a simple, purely topological, cellular model which is allowed to evolve through a Glauber-Kawasaki process. We find a non-thermodynamic transition to a glassy phase in which the energy (defined as the square of the local cell topological charge) fails to reach the equilibrium value below a characteristic temperature which is dependent on the cooling rate. We investigate a correlation function which exhibits ageing behaviour, and follows a master curve in the stationary regime when time is rescaled try a factor of the relaxation time t(r). This master curve can be fitted by a von Schweidler law in the late beta -relaxation regime. The relaxation times can be well fitted at all temperatures by an offset Arrhenius law. A power law can be fitted to an intermediate-temperature regime; the exponent of the power law and the von Schweidler law roughly agree with the relationship predicted by mode-coupling theory. By defining a suitable response function, we find that the fluctuation-dissipation ratio is held until sometime later than the appearance of the plateaux; non-monotonicity of the response is observed after this ratio is broken, a feature which has been observed in other models with dynamics involving activated processes.
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页码:8615 / 8625
页数:11
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